US2173652A - Vehicle spring suspension - Google Patents

Description

Sept. 19, 1939. R. K. LEE, ET AL 2,173,652

VEHICLE SPRING SUSPENSIQON Filed May 31, 1933 2 Sheets-Sheet l lNVlNTOR. .HOGER K. LEE CLARK A. TEA.

I BY%;7

A TTORNEYJ Sept. 19, 1939. R. K. LEE ET AL 3 3.6

VEHICLE SPRING SUSPENSION Filed May 31, 1953 A .2 Sheets-Sheet. 2

INVENTOR.

ROGER K. LEE.

CLARK A. TEA.

' 7 ATTORNEYS Patented Sept. 19, 1939 PATENT. oFF c-E.

VEHICLE SPBIN G SUSPENSION Roger K. Lee, Highland Park, and out a. Tea,

Detroit, Mich, assignors to Chrysler Corporation, Detroit, Micla, a corporation of Delaware ' Application M... 31, 1933, Sam No. 013.709

12 Claims. (01. 267-57) This invention relates to motor vehicles, and more especially to the spring suspension system eof. The principal object of the invention is to pro- 5 vide an improved spring suspension system for motor vehicles.

Another object is to reduce to a minimum the unsprung weight of a motor vehicle.

Another object is to precondition a spring sus- 10 pension system of a motor for different loads.

Another object is to provide a spring suspension system for motor vehicles which prevents pitching of the vehicle body regardless of the load distribution therein.

Another object is to provide; a spring suspension system wherein a deflection of the front springs causes a corresponding-deflection in the same direction of the rear springs of the vehicles.

Another object is to provide a spring suspension system in which the resistance to spring deflection is increased at a greater rate as the springs are deflected beyond a predetermined point.

Another object is to provide a spring suspeng5 sion system in which there is a gradual transition from one rate of increase of resistance to spring deflection to a greater rate of increase of resistance to spring deflection as the deflection of the springs is increased.

Other objects and advantages will become apparent from the following description and appended claims.

For the purpose of illustrating the genus of the invention, typical concrete embodiments 35 thereof are shown in the accompanying drawings in which: s

Figure 1 is a perspective,- more or less diagrammatic in form, of the arrangement of front and rear springs of a motor vehicle constructed in accordance with this invention;

Fig. 2 is a side elevation'of the construction shown in Fig. 1;

Fig. 3 is an enlarged view in side elevation of parts shown in Figs. 1 and 2; i

Fig. 4 is an elevation with parts broken away and in section of another embodiment of spring suspension means according to this invention;

Fig. 5 is an end view of parts shown in Fig. 4:

, Fig. 6 is a view similar to Fig. 5, with parts 50 broken away to show a section taken on the line 8-6 of Fig. 4, construction lines being shown to indicate the position of parts during the deflection of the springs and the "direction of applica- I tion of a force producing such deflection;

Fig. '7 is a diagram showing the relation of the deflection and resistance to deflection springs, shown in Figs. 4, 5 and. 6;

Fig. 8 is a central longitudinal section of v a further modification of spring suspensionmeans constructed in accordance with this invention; 3 Fig. 9 is an end view of parts shown in- Fig. 8; Fig. 10 is a section taken on the line l0lll of Fig. 8; and A Fig. 11 is a diagram similar to that shown in Fig. 7 but additionally illustrating the relation of 10.

ofthe,

the deflection and resistance to deflection'of the spring suspension means shown in Figs. 8, 9 and 10.

Referring to Figs. -1, 2 and 3 of the drawings, one of the spring suspension means according to 15 this invention is-illustrated. ,In this embodiment the numeral l0 designates the frame of the motor vehicle, which frame may be a more or less conventional type of chassis frame but preferably constitutes a combined chassis arid body frame of the vehicle, as illustrated. The frame l0 includes a pair of side sills H, and front and rear cross members designated as i2 and II respectively. An intermediate cross member I4 extends transversely of the frame and is connected'to the side sills H. A support member 15 extends longitudin'ally of the frame It and its ends are connected to the central portions the cross members l2 and II. The inner ends of a pair, of torsionally yieldable members It are welded or otherwise secured to the supporting member IS, the torsionally yieldable members [8 extending transversely of the frame ill ,to points beyond the side sill l I. A pair of arms I! are secured to the outerends of the torsionally yieldable members It and extend forwardly of the frame loin a generally horizontal direction when supporting the vehicle and load. To the forward ends of the arms II are pivoted the 'steering'knuckles of the front wheels 20. 'I'he arms II are bowed inwardly to 40 permit steering of the wheels 20 and preferably are provided with brace members It extending from a point adjacent the pivotal connection to the steering knuckles to a point adjacent the connection of the torsional membersi 6 to the support 4 member IS. The rearwardly disposed ends of the brace members II are journaled on the torsionally yieldable members It and retained in position on the yieldable members by means of the support member l5 and collar member 22 B0 locked to the torsionally yieldable members I8. The torsionally members It may be of any desired cross section although preferably cylindrical, and may be of tubular or solid formation. Bearing members 23 are secured to the bottom portion of 68 the side sills II and aiford bearings for the torsionally yieldable members It at points intermediate their lengths.

At the rear portion of the frame II! a pair of torsionally yieldable members are provided, each being fixed at one end to a side sill of the frame I!) and extending to a bearing secured to the opposite side sill and beyond the latter sill to an arm 26 secured on the end of the yieldable member, -as by means of a pin 28. Wheels 21 are journaled upon the rear endsof the arms 26. Both the torsionally yieldable members 25 and the arms 26 are made of greater length than the yieldable members l6 and arms l1 employed at the front end of the vehicle. This causes the rear spring means to exert less torsional resistance to deflection relative to the rear wheels of the vehicle than that afforded by the front spring means relative to the front wheels. Both the lengthening of the torsionally yieldable-members and the lengthening of the arms decrease the stifiness of the spring suspension means relative to the wheels of the vehicle so that either or both expedient s may be employed, preferably both, as illustrated. I

Referring to Fig. 1 it will be noted that the effective length of the arms I! and 26 are designated Ll'and L2 respectively, and the resultant forces acting in a vertical direction upon the axes of the front and rear wheels are designated RI plus FI and R2 plus F2, respectively. When the front wheels strike a bump, the moment of forces acting upon the springs l6 will be (RI +Fl) Ll, and the balancing moments of forces acting upon the spring 25 will be (R2+F2) L2, and these moments will be equal. Since the stiffness of the tension spring 25 is much less than that of the spring l6, and the length of the arm L2 is greater than that of the arm LI, the rear end of the vehicle will be depressed upon depression of the front end of the vehicle for the moments to balance. Thus, if the front end of the vehicle at the bearings 23 is moved up and down, the body will not rotate about its center of gravity or about the axis of either spring; but the body, as a whole, will move more or less vertically due to the reaction of relatively stiif front springs on relatively less torsionally resistant rear springs.

. If, however, the rear wheels of the vehicle encounter bumps the action of the relatively weak rear springs will have little eflect on the action of the relatively still front springs, the rear end of the body being moved up and down and rotating about a point near the bearing 23. This difference in the reaction of the front and rear springs as the front and rear wheels respectively encounter uneven road surfaces precludes the possibility of pitching of a vehicle body regardless of i the weight distribution therein.

In the design of a five-passenger automotive-vehicle it is extremely difficult to select the proper spring suspension means which will aflord the desired riding qualities both when the vehicle carries one and five passengers. This is especlally true in the case of a light vehicle in which the variation in loads between one and five passengers may be substantially equal to the weight.

of the vehicle. In the present construction provision is made for preconditioning the springsuspension system for different loads. Since the variable load of an automotive vehicle is carried principally by the rear springs, the present construction makes provision for rotatively adjusting the fixed ends of the torsionally yieldable members 25. This may be effected by providing a pair of supports clamped or otherwise secured to the side sills ll of the frame II, the upper portion of the supports 30 providing bearings for the upper spring member 25 and the lower portion, bearings for the lower spring member 25. Ratchet segments 3| are fixed to the ends of the spring members 25 and are engageable with means for rotating the spring members to the desired adjusted position. It is preferred to arrange the spring members 25 one above the other, to permit the arms 26 to be of approximately equallengths. To prevent endwise displacement of the yieldable members 25 relative to the supports 30 a collar 32 may be fixed thereto 'upon the opposite side of the bearing afforded by the support member 30 -from' each ratchet member 3| The operating means for the ratchet member 3| preferably comprises'a pair of pawls 33 and 34, the pawl 33 being a holding pawl and pivoted to to the end of an operating lever 36 which in turn is pivoted to the support member 35 by a pivot pin 31. The ratchet operating mechanism is adapted to rotate the ratchet 3| in a clockwise direction and in a step-by-step manner upon oscillation of the operating lever 36 between the position indicated in full lines in Figs. 1, 2 and 3 and the position indicated by dot-and-dash line 40 of Fig. 2. Rotation of the ratchet members 3| in a clockwise direction will rotate the arm 26 in a corresponding direction when the load in the vehicle remains unchanged and will permit the arm 26 to remainin a substantially horizontal position upon deflection of the yieldable members 25 as the load in the vehicle is increased. Oscillation of the operating lever 36 between the position indicated in full lines and the position indicatedby dot-and-dash line 4| in Fig. 2 will permit counter-clockwise rotation of the ratchet member 3| in a step-by-step manner under the influence of the load of the body and chassis of the, vehicle relative to the wheels 21.

In the ratchet operating mechanism the holding pawl 33 is normally biased into engagement with the teeth of a ratchet segment 3| by means of a spring 42 secured to thesupport member 35. A light coil spring 43 is arranged in tensionedcondition between the pivot pin 31 for the operating lever 36, and a laterally extending lug 44 provided on theside of the operating pawl 34. The spring 43 normally tends to keep the pawl 34 out of engagement with the teeth of the ratchcammed surface 45 of the holding pawl. The

spring 46 is of suflicient strength to overcomeat certain times the biasing action of the spring 42 to disengage the holding pawl 33 from the teeth of the ratchet segment 3 A leaf spring 41 is secured to the upper surface of the operating lever 36 at a point adjacent the pivot 31 and 'extends to apoint adjacent the upper surface of the spring 46 when the parts are in the position indicated in full line in Figs. 1, 2 and 3. The spring 41 is made of sufficient strength to overcome the biasing action of the coil spring 43 and engages the upper surface of theleaf spring 46 as a the operating lever 33 is rotated in a clockwise direction to. yieldabiy urge the operating pawl 34 into engagement with ,the teeth of the ratchet segment 3|. The operating levers 36 of the ratchet operating mechanism extend upwardly into the body of the vehicle and the upper ends are connected by a cross member 33 which may afford a foot rail for the rear compartment of the vehicle In the operation of the ratchet operating mechanism the ratchet segments 3| may be rotated in a clockwise direction in a step-by-step manner by oscillating the lever 36 between the fulllined position and that indicated by the dot-and-dash line 46 of Fig. 2, as previously indicated. During this operation the spring 46 is separated from contact with the cammed surface 46 so that the spring 42 can yieldably maintain the holding pawl 33 in contact with the teeth of segment 3| while at the same time the spring 41 engages the upper surface of spring 46 and overcomes the biasing action of the coil spring 43 to maintain the operating pawl yieldably in engagement with the teeth of the segment 3|. During this operation no elements of the mechanism function to separate the holding and operating pawls from the teeth of the ratchet segments so that the operating pawl successively picks up teeth of the segment 3| and advances the segment in a clockwise direction to such a point that the holding pawl may retain-the segments in position while the operating pawl picks up the next successive tooth.

In the operation of the segment actuating mechanism to lower the rear portion of the body relative to the wheels 21, the operating handle 36, aspreviously indicated, is oscillated between the full lined position and the position indicated by the dot-and-dash line 4| in Fig. 2, which op. eration of the lever 36 toward the dot-and-dash line 4| first brings the spring 46 into engagement with the cammed surface to force the teeth of the operatingpawl 34-into engagement with the teeth of the ratchet'segment 3|. The spring 41 is not in engagement with the spring 46 at this time and the spring 46 is oi! suflicient strength to overcome the biasing action of the spring 43 but cannot move the holding pawl 33 away from the teeth since the load of the vehicle body at this time is carried by the holding pawl and frictional engagement between the teeth of the holding pawl and the segment maintains the holding pawl in engagement with the ratchet segment until the teeth of the operating pawl 34 pick up the load. As the load is picked up by the operating pawl, the spring 46 co-operates with the cammed surface 45 to move the holding pawl .33 out of engagement with the teeth of the ratchet segment, the spring 46 overcoming the biasing action of the spring 42 at this time. As the operating lever 36 moves from the position indicated by the dot-and-dash lines 4| toward the full-line position, as indicated in Fig. 2, the operating pawl 34 moves away from the holding pawl 33 withdrawing the spring 46 but holding the holding pawl 33 out of engagement with the ratchet segment'3l until the teeth thereof have passed the points of the teeth which were previously held thereby until the spring 46 is so far out of engagement with the holding pawl 33 that the spring 42 may return the holding pawl into engagement with the next successive teeth above those previously held as indicated in Fig.- 3. As the spring 46 is moved out of engagement with the cammed surface 45v of the holding pawl, the spring 43 retracts the operating pawl 34 from engagement with the teeth of the ratchet segment as the holding pawl assumes the load. As the operating handle 36 is again rotated in a counterclockwise direction from the full-lined position to the position indicated by the dot-and-dash line 4-|. the coil spring 43 maintains the operating pawl 34 out of engagement with the ratchet segment until the teeth of the operating pawl have passed the teeth of the ratchet segment previously held thereby until such time as the spring 46 again engages the cammed surface 46 forcing the teeth oi the operating pawl into engagement with the next successive teeth of the ratchet segment above those previously held. Continued oscillation of the operating lever 36 causes the operating pawl 34 to again pick up the load and cause the release of the holding pawl until a tooth of the ratchet segment has passed the same whereupon the holding pawl ag'ain picks up the load. In this manner the operating lever 36 may be oscillated between the limits indicated to either raiseor lower the rear portion of the vehicle relative to the wheels to compensate for the torsional deflection of the yieldable member 25 so that the arm 26 may be maintained in substantially horizontal position for variable loads disposed in the body of the vehicle. p

Referring particularly to Figs. 4 to '7 inclusive, another embodiment of spring means is disclosed which may be employed in place of the spring means indicated at |5 or 25 of the previously de-- scribed embodiments. Referring to the c nstructionshown in Figs. 4 to 6 inclusive, a su port 50 is shown indicative of a support such as l5 or II of the previously described embodiments, to which is'secured one end of a solid cylindrical and torsionally yieldable, member 5|. An arm 56 is secured to the outer end of the torsionally yieldable member 5| by means of a pin 23. A bearing 53 supports theouter end of the yieldable member 5| in the same manner as dothe bearings 23 and 36 of the previous embodiment. A second tubular member 52 is secured at one end to thesupport 50 as by means of the bolts 54 and surrounds the torsionally yieldable member 5| through a major. portion of its length. The torsionally yieldable member 52 is provided with a slot 51 adjacent its outer end which is adapted to cooperate with lug when the torsional deflection of the yieldable member 5| has reached a certain value. The sides of the slot 61 are spaced from the lug 60 so that the, torsionally yieldable member 5| may be deflected to a certain extent without the lug 60 engaging the sides of the slot 51 but continued deflection thereafter causes the yieldable member 6| to pick up the yieldable member 52 so that both yieldable members from that point resist torsional deflection. Referring to Fig. 6 the deflection produced by a force? applied to the end'of the arm 56, that is at the point of connection tothe wheels of the vehicle, gives the efl'ective vertical distance of travel of the axes of the Wheels, as indicated by. 41. Since the deflection is proportional to the force applied, to the square of the length of the arm 56 and to the length of the torsionally yieldable member and inversely pro-- portional to the modulus of elasticity for torsion of the material composing the torsionally yieldable members, and inversely proportional to the fourth power of the diameter of the torsonally yieldable member; the stiffness of thesprings may be. controlled by the selection of material point adjacentits free end of the force or load producing such deflection are plotted along the ordinate of the diagram. The value of deflection dl designates the deflection produced by the vehicle body with no c0ntained load, d2 the deflection with two passengers in the vehicle and d3 with four passengers in the vehicle. In the absence of any positive connection between the torsionaily yieldable members 5| and 52 such as the lug 80, the relation between deflection and force producing such de'- flection would be represented by a straight line such as 6|, 6|. With the torsionally yieldable members 5| and 52 connectedas by the lug 80,

the rate of resistance to torsional deflection increases at a greater rate as indicated by the line 62. Thus in the spring construction disclosed in Figs. 5 to 6 inclusive the torsionally yieldable member 52 increases the rate of resistance to deflection as the spring is deflected beyond a predetermined pointj Referring to Figs. 8, 9 and 10, a slightly modifled form of construction of the spring means disclosed in Figs. 4 to 6 inclusive is illustrated. In this embodiment a tubular and torsionally yieldable member i2 is secured to a support. 18 by means of bolts 18. The tubular member I2 has welded thereto a sleeve member 18 which is welded in turn to a torsionally yieldable member II which is enclosed by and extends slightly beyond the end of the tubular member 12. The free end of the torsionally yieldable member H issecured to the end of an arm 88 corresponding to arms i1, 28 and 58 of previous embodiments and which is secured to a flange 8| integral with a sleeve member 82 by means of bolts 83. The free end of the torsionally yieldable member 12 is provided with a disc-like enlargement 85. The inner end of the sleeve member 82 is provided with a similar disc-like .en-

largement and the enlargements 88 and 88 are provided with cooperating specter-shaped lugs 81 which through the intermediary of spectorshaped lugs terial are adapted to cause a deflectionof the yieldable member 12 upon the deflection of the yieldable member Ii beyond a predetermined point. A bearing 84, corresponding to'the bearlugs 23, and 88 of the previous embodimmts, is provided for the yieldable member II at a and in the present instance surrounds the sleeve 82.

Referring to Fig. 11, the relation between load,

and deflection is diagrammatically illustrated in the same manner as in Fig. 7. In the absence of the block 88 of yieldable material interposed between the cooperable lugs 81 which are fixed respectively relative to the yieldable members H and 12, the relation of-deflection to resistance to' deflection of the yieldable member H would be represented by the straight line H for deflections up to that represented by d2, at which point the tubular member I2 would be picked up and from then on the relation of deflection to resistance to deflection of both tubular members H and 12 would be represented by the line 82 of Fig. 11. During operation otthe vehicle de- 88 of rubber or other yieldable ma- I flection of a value approximately that represented by d2 would cause engagement and disengagement of the lugs 81 and render the action of the spring disagreeable and uncomfortable to occupants of the vehicle. By interposing the resilient block between the lugs 81, the tubular yieldable member is picked up earlier-and the rate of increase of resistance to torsional deflection of the combined springs is represented by the dotted line 88. By providing the yieldable block 88 the rate of change of resistance to torsional deflection of the spring is gradually varied from that of the yieldable member ll alone to that of the combined yieldable members H and 12 thus smoothing out the action of the spring.

As many changes could be made in the above construction and many apparently different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall ,be interpreted as illustrative and not in a limiting sense.

What we claim is:

1. In a motor vehicle including a frame and pairs of front and rear wheels for supporting said frame, the combination of torsionally yieldable members for each wheel, each member being non-rotatably secured at one end to said frame and rotatably connected at a point intermediate their length to said frame, an arm fixed at one end to each torsionally yieldable member and rotatably connected to one of the wheels at the other end, the resistance to torsion of the yieldable members connected to the rear wheels being less than that of the yieldable members connected to the front wheels.

2. In, a motor vehicle including a frame and pairs of front and rear wheels for supporting said frame, the comlnation of torsional yieldable members for each'wheel, each yieldable member being non-rotatably secured at one end to said frame and rotatably connected at a point intermediate its length to said frame, an arm flxed at one end to each torsionally yieldable member and rotatably connected to one of the wheels at the other end, the length of the arm connected to the rear wheels being greater than that of the arm connected to the front wheels. 3. In a motor vehicle including a frame and a wheel, the combination of a spring suspension means interconnecting said frame and wheel comprising a torsionally yieldable member fixed at one end to said frame, bearing means on said frame for iournaling said yieldable member at a point remote from the flxed'end thereof, an.

flected beyond a predetermined point.

4. In a motor vehicle including a frame and a wheel, the combination of a spring suspension comprising a torsionally yieldable member fixed at one end to said frame, bearing means on said frame-for journaling said yieldable member at a point remotefrom said fixed endthereof, an arm fixed at one end to said yieldable member and arranged substantially normal to the latter, the

other end of said arm being rotatably connected to said wheel, a tubular and torsion lly'yieldable member disposed on said flrst-named yieldable 75 65 means interconnecting said frame and wheel I yieldable member, and means arranged adjacent the opposite end of the first-named member for engaging the opposite end of the tubular memher after the first-named member has been deflected beyond a predetermined point and thereafter to cause deflection of the tubular member upon continued deflection of the first-named member.

5. In a motor vehicle including a frame and a wheel, the combination of a spring suspension means interconnecting said frame and wheel comprising a torsionally yieldable member fixed at one end to said frame, bearing means on said frame for journaling said yieldable member at a point remote from the fixed end thereof, an arm 1 arranged substantially normal to the yieldable -member and fixed at one end to the latter, the

wheel thereon, means for increasing the rate of resistance to torsional deflection as said yieldable member is deflected beyond a predetermined point, and means for; effecting a gradual change 5 from one rate of increase o'f-resistance to tor- '1. In a motor vehicle including a frame and a" wheel, the combination of a spring suspension means interconnecting said frame and wheel and comprising a pair of torsionally yieldable memberseachfixed atoneendtosaidframe,anarm fixed at one end to an end of one of said members and rotatably connected to said wheel at its other end, lugs fixed to each of said members for rendering one effective only after a prede-' termined deflection ofthe other, and a rubber block interposed between said lugs for ca m a gradual changeinthe'rateofreaistancetodeflectionfromthat of one member to-that of both members.

-8.Inamotorvehicleincludingaframeanda wheeLthecombinationofasprIngsmpension means interconnectingsaidframeandwhaeland comprising a torsionally yieldable member extendingtransverselyof and-finedatoneendto saidframeandawheelmportincludinganarm fixedatoneendtcthcotherendofsaidmemberandrotatabiyconnectedtosaidwheclatthe .otberendandincludingmeansincngamt other end of said arm rotatably supporting said with said member for holding the end of said arm connected to the wheel from deflection relative to the fixed end of said torsionally yieldable memher.

9. In a motor vehicle including a frame and wheel, the combination of a spring suspension means interconnecting said frame and wheel and comprising a torsionally yieldable member fixed at one end to said frame, an arm fixed at one end to the other end of said torsionally yieldable member and rotatably connected at its other end to said wheel, and a second arm fixed at one end v to said torsionally yieldable member at a point spaced from said other end thereof and fixed to said first named arm adjacent said wheel for holding the interconnected ends of said arms against deflection relative to the fixed end of said torsionally yieldable members.

10. In a motor vehicle including a frame and a pair of laterally spaced wheels, the combination with a pair of spring suspension means, each including'a torsionally yieldable bar extending laterally of said vehicle and flxed at one end to said frame, bearing means on said frame for independently journaling each yieldable member respectively at a point remote from its fixed end, a wheel support on each of said bars includin a pair of converging arms having one of their non-adjacent ends journaled on the fixed end portion of one of said bars and the other of their non-adjacent ends fixed to the opposite ends thereof respectively, and a wheel spindle on the adjacent ends of the converging arms of each wheel support.

11. In a motor vehicle including a frame and a pair of spaced wheels, the combination with a pair of spring suspension means including a pair of torsionally yieldable members extending laterally of said vehicle and fixed at one end to said frame, bearing means on said frame for independently joumaling each yieldable member respectively at a point remote from its 'fixedend, a wheel support on eaclr of said members includ- -ing apair of converging arms having one of their non-adjacent ends fixed on one of said members means, and a wheel spindle on the adjacent ends of the converging arms ofeach wheel support.

12'. In a motor vehicle chassis including a wheel, a frame, a torsionally yieldable member x. m. manual-1m.

and the other of their nonadiacent ends journaledonsaidmemberspacedfromsaidbearing

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